Display Apparatus and Method for Driving Display Panel

The present application claims priority to Chinese Application No. 202510264848.3 with the application title of “DISPLAY APPARATUS AND METHOD FOR DRIVING DISPLAY PANEL”, filed on Mar. 6, 2025, the content of which is incorporated herein by reference in its entirety.

The present disclosure relates to the field of display technologies, and in particular, to a display apparatus and a method for driving a display panel.

With continuous development of science and technologies, more and more electronic equipment with display functions are widely used in people's daily life and work, bringing great convenience to people's daily life and work, and becoming an indispensable and important tool in modern society. A main component of the electronic device which realizes the display function is a display panel.

In the Multi-frequency Display (MFD) technology, the display panel includes at least two display regions driven at different frequencies. Currently, there is a problem of uneven brightness between display regions driven at different frequencies.

An aspect of the present disclosure provides a display apparatus. The display apparatus includes a display panel and a drive controller. The display panel includes a first display region and a second display region. The drive controller is configured to calculate a difference of image data between a current frame and a previous frame, and enable the display panel to operate in a multi-frequency mode or a conventional mode according to the difference. In the multi-frequency mode, the first display region has a different drive frequency from the second display region. In the conventional mode, the first display region has a same drive frequency as the second display region.

Another aspect of the present disclosure provides a method for driving a display panel. The display panel includes a first display region and a second display region. The method includes: calculating a difference between image data in a current frame and image data in a previous frame, and enabling the display panel to operate in a multi-frequency mode or a conventional mode according to the difference. In the multi-frequency mode, the first display region has a different drive frequency from the second display region. In the conventional mode, the first display region has a same drive frequency as the second display region.

In order to better understand technical solutions of the present disclosure, embodiments of the present disclosure are described in detail below in conjunction with the drawings.

It should be noted that, the described embodiments are merely some but not all of the embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those ordinary skilled in the art shall fall within the protection scope of the present disclosure.

Terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments, and are not intended to limit the present disclosure. The terms “a/an”, and “the/said” in a singular form in an embodiment of the present disclosure and the attached claims are also intended to include plural forms thereof, unless explicitly noted otherwise in the context.

It should be understood that the term “and/or” used herein is merely an association relationship describing an associated object, and indicates that there may be three relationships, for example, A and/or B, and may indicate only A, both A and B, and only B. In addition, the symbol “/” in the context generally indicates that the relation between the objects in front and at the back of “/” is an “or” relationship.

An embodiment of the present disclosure provides a display apparatus, which may be any device having a display function, such as a mobile phone, a tablet computer, a laptop computer, an electronic paper book, a television, and a smart watch. As shown in, which is a schematic diagram of a display apparatus according to an embodiment of the present disclosure, the display apparatus includes a display paneland a drive controller, and the drive controlleris configured to drive the display panelto display.

In an embodiment of the present disclosure, as shown in, the display panelincludes a first display region Aand a second display region A. The first display region Aand the second display region Ainclude a plurality of sub-pixels, respectively.

In an embodiment of the present disclosure, the drive controlleris configured to calculate a difference of image data between a current frame and a previous frame, and enable the display panelto operate in a multi-frequency mode or a conventional mode according to the difference. In the multi-frequency mode, a drive frequency of the first display region Ais different from the drive frequency of the second display region A. In the conventional mode, a drive frequency of the first display region Ais the same as a drive frequency of the second display region A.

In an embodiment, with reference toand,is a circuit diagram of a sub-pixel according to an embodiment of the present disclosure, and the sub-pixelincludes a pixel drive circuitand a light-emitting elementthat are electrically connected. The pixel drive circuitis configured to drive the light-emitting elementto emit light. The pixel drive circuit receives the first power voltage PVDD and the data voltage DATA, and generates the drive current according to the first power voltage PVDD and the data voltage DATA.

In an embodiment of the present disclosure, as shown in, the pixel drive circuitincludes a first thin film transistor T, a second thin film transistor Tand a storage capacitor Cst. A first electrode of the first thin film transistor Tis electrically connected to the data voltage terminal DATA. A second electrode of the first thin film transistor Tis electrically connected to a gate electrode of the second thin film transistor T, and a gate electrode of the first thin film transistor Tis electrically connected to the scan signal terminal S. One of the first electrode and the second electrode is a source electrode, and the other one is a drain electrode. A first electrode of the second thin film transistor Tis electrically connected to the first power supply voltage terminal providing the first power supply voltage PVDD, and a second electrode of the second thin film transistor Tis electrically connected to the light-emitting element. The light-emitting elementis electrically connected to a second power supply voltage terminal providing a second power supply voltage PVEE. The first electrode plate of the storage capacitor Cst is electrically connected to the first power supply voltage terminal providing the first power supply voltage PVDD, and the second electrode plate of the storage capacitor Cst is electrically connected to the gate of the second thin film transistor T. The current flowing through the light-emitting elementis related to the gate-source voltage difference of the second thin film transistor T, that is, related to the data voltage DATA and the first power supply voltage PVDD.

In an embodiment, as shown in, the display panelfurther includes a scan line SL and a data line DL electrically connected to the sub-pixel. The scan line SL is electrically connected to the scan signal terminal S of the pixel drive circuit. The data line DL is electrically connected to the data voltage terminal DATA of the pixel drive circuit.

As shown in, the display apparatus further includes a gate drive circuitand a data drive circuit. The gate drive circuitprovides a scan signal S (labeled the same as the scan signal terminal S of the pixel drive circuit) to the scan line SL. The data drive circuitis configured to provide a data voltage DATA (labeled the same as the data voltage terminal DATA of the pixel drive circuit) to the data line DL according to the image data.

In an embodiment of the present disclosure, the drive frequency may be understood as a frequency of refreshing the data voltage DATA written into the pixel drive circuit. That is, a frequency of an enable level of the above scan signal S.

As shown in, the gate drive circuitmay be electrically connected to the drive controller. In an embodiment of the present disclosure, the drive controllermay separately send, in response to signals corresponding to different differences, a first mode control signal corresponding to the multi-frequency mode and a second mode control signal corresponding to the conventional mode.

Under the action of the first mode control signal, the gate drive circuitmay make the frequency of the enable level of the scan signal S provided to the first display region Ato be different from that of the enable level of the scan signal S provided to the second display region A.

Under the action of the second mode control signal, the gate drive circuitmay make the frequency of the enable level of the scan signal S provided to the first display region Ato be the same as that of the enable level of the scan signal S provided to the second display region A.

In an embodiment of the present disclosure, in the multi-frequency mode, display images of the first display region Aand the second display region Amay be different. The drive controllermay determine the drive frequency of the display region according to a type of the image to be displayed in the display region, such as a still image or a moving image. For example, the first display region Amay display the moving image, such as a video. The second display region Amay display the still image, such as a text or a picture. In the multi-frequency mode, a drive frequency of the first display region Amay be greater than a drive frequency of the second display region A. That is, the first display region Ais a high-frequency region, while the second display region Ais a low-frequency region. In an embodiment, the difference may be a difference of the image data between the current frame and the previous frame in the first display region A.

In the process of implementing the embodiments of the present disclosure, the inventors have found that: In the case that the load difference corresponding to the image data in two adjacent frames is significant, the signal on the first power supply line for providing the first power supply voltage PVDD in the display panelmay change greatly, thereby affecting the current flowing through the light-emitting element and affecting the brightness of the light-emitting element. If the display panel drives the first display region Aand the second display region Aat different frequencies at this time, there will be a large difference in brightness between the two, resulting in a screen flickering problem.

With reference toand,is a schematic diagram of a partition of a display panel according to an embodiment of the present disclosure, andis a schematic diagram of brightness changes at different positions in the first display region and the second display region shown inin different time periods. The first display region Ais driven at 120 Hz. The second display region Ais driven at 10 Hz. Time periods Fto Fare refresh frames of the first display region A, the time period Fis a refresh frame of the second display region A, and time periods Fto Fand time periods Fto Fare skip frames of the second display region A. That is, the second display region Aperforms data voltage refresh during period F, and does not perform the refresh of the data voltage during time periods Fto Fand time periods Fto F.

Taking the image data received at the position {circle around (4)} in the first display region Ain the time period Fbeing switched from 255 grayscale (Wshown in) to 0 grayscale (Wshown in) as an example, a large change in the display grayscale will cause a significant change in the load of the display panel, thereby causing a significant change in the first power supply voltage PVDD received by the pixel drive circuit, resulting in a change in the brightness of the position {circle around (3)} in the first display region A.

And the second display region Ais in the stage of not refreshing data during the time period F. As shown in, the voltage change on the first power supply voltage terminal PVDD affects the Nnode in the pixel drive circuitin the second display region Athrough coupling. Therefore, the second display region Acan maintain the brightness of the previous stage at this time, thereby causing a significant difference between the brightness of the first display region Aand the brightness of the second display region A. As can be seen from, the brightness difference period between the first display region Aat the position {circle around (2)} and the second display region Aat the position {circle around (1)} lasts from the time period Fto the time period F.

In an embodiment of the present disclosure, the drive controlleris provided in the display apparatus, the difference of the image data between the current frame and the previous frame is calculated by the drive controller, and the display paneloperates in the multi-frequency mode or the conventional mode according to the difference.

For example, when the difference is relatively large, the drive controllermay control the display panelto operate in the conventional mode, that is, the first display region Aand the second display region Aare driven at the same frequency. Taking the example shown in, where position {circle around (4)} in the first display region Aswitches from a 255 grayscale to a 0 grayscale during time period F, although this drastic grayscale transition may cause a significant fluctuation in the first power supply voltage (PVDD), the method proposed in this embodiment ensures that both the first display region Aand the second display region Arefresh their data voltages during this time period, which allows the brightness variation of both display regions to be similar, thereby reducing or even eliminating brightness difference between them, improving the brightness consistency of the display panel, and thus enhancing the display effect.

When the difference is small, the drive controllermay control the display panelto operate in the multi-frequency mode, for example, in the embodiments of the present disclosure, the first display region Amay be driven at a high-frequency, and the second display region Amay be driven at a low-frequency, thereby improving the image fluency of the first display region Aand reducing the power consumption of the second display region A.

It should be noted that the pixel drive circuitshown inis merely illustrative, and the structure of the pixel drive circuitmay also be designed differently according to different design requirements, for example, the pixel drive circuitmay be designed as a “7T1C” structure including 7 thin film transistors and 1 storage capacitor, and the specific structure of the pixel drive circuitis not limited in the embodiments of the present disclosure.

In an embodiment, in this embodiment of the present disclosure, positions of the first display region Aand the second display region Amay be fixed, or may change according to a change of the to-be-displayed image.

In an embodiment of the present disclosure, when the difference is greater than the first preset value, the drive controlleris configured to enable the display panelto operate in the conventional mode. When the difference is less than or equal to the first preset value, the drive controlleris configured to enable the display panel to operate in the multi-frequency mode.

In an embodiment, the first preset value may be set according to structural and performance requirements of the display panel, which is not limited in the embodiments of the present disclosure.

In an embodiment of the present disclosure, as shown in, which is a modular schematic diagram of a drive controller according to an embodiment of the present disclosure, and the drive controllerincludes a difference calculation unitand a mode determination unit. The difference calculation unitis configured to calculate a difference of image data of any sub-pixel between a current frame and a previous frame, and send the difference to the mode determination unit. The mode determination unitis configured to enable the display panelto operate in a multi-frequency mode or a conventional mode according to the difference.

In an embodiment, the mode determination unitmay be electrically connected to the gate drive circuitshown in. Mode determination unitmay issue a mode control signal in response to signals issued by difference calculation unitcorresponding to different differences. For example, the mode control signal includes the first mode control signal corresponding to the multi-frequency mode and the second mode control signal corresponding to the conventional mode.

In an embodiment of the present disclosure, the difference calculation unitincludes a current calculation sub-unit, and the current calculation sub-unit is configured to calculate a drive current of any sub-pixelin a corresponding frame, and use the drive current as image data of the sub-pixelin the corresponding frame. The drive current WAPLn of any sub-pixelsatisfies:

where k is a coefficient corresponding to the sub-pixel, coefficients k corresponding to sub-pixelswith different light-emitting colors may be different, Gray is a grayscale of the sub-pixelin a corresponding frame, and Gmax represents a peak grayscale. For example, when the display panelsupports 8-bit grayscale voltage resolution, the peak grayscale is 255.

In an embodiment of the present disclosure, the difference ΔWAPLn of the image data between the current frame and the previous frame satisfies:

Gray1 is a grayscale of the sub-pixelin a current frame, and Gray2 is a grayscale of the sub-pixelin a previous frame. Based on this arrangement, the difference of image data between the current frame and the previous frame may be obtained according to the grayscales of the sub-pixelsin two adjacent frames, and then the operation mode of the display panelmay be determined according to the difference.

In an embodiment, as shown in, which is a modular schematic diagram of another drive controller according to an embodiment of the present disclosure, and the drive controllerfurther includes a frequency acquisition unitand a duration setting unit. In an embodiment of the present disclosure, when a difference between the image data in a current frame and the image data in a previous frame is greater than the first preset value, the frequency acquisition unitis configured to obtain an occurrence frequency at which the difference is greater than the first preset value, and send the occurrence frequency to the duration setting unit. The duration setting unitis configured to control an operating duration of the display panelin the conventional mode according to the occurrence frequency.

In an embodiment of the present disclosure, the duration setting unitis configured to control the operating duration of the display panelin the conventional mode to be a duration of one frame when the occurrence frequency is less than or equal to a first reference frequency. In an embodiment of the present disclosure, when entering the next frame, the difference calculation unitmay continue to calculate the difference between the image data in the two adjacent frames in real time, and adjust the operation mode of the display panelin real time according to the difference.

In addition, when the occurrence frequency is greater than the first reference frequency, the duration setting unitmay control the operating duration of the display panelin the conventional mode to be greater than the duration of one frame, and the difference calculating unitmay stop calculating the difference between the image data in two adjacent frames during a time period in which the display panel operates in the conventional mode. Based on this arrangement, when the occurrence frequency at which the difference of the image data between the current frame and the previous frame is greater than the first preset value is relatively high, the operating duration of the display panelin the conventional mode may be prolonged, thereby avoiding frequent switching between the conventional mode and the multi-frequency mode of the display panel. On the one hand, it can reduce the power consumption of the display apparatus, save computing power, and on the other hand, it can also avoid the flickering problem of the display panel caused by frequent switching of operation modes.

In an embodiment, as shown in, which is a schematic diagram of a display apparatus according to another embodiment of the present disclosure, the display apparatus further includes a voltage drop compensation unit, and the voltage drop compensation unitis configured to compensate for a voltage drop (IR drop compensation, IRC) of the first power supply voltages PVDD received by different sub-pixelswith the data voltage DATA. For example, when the difference between the image data in two adjacent frames is relatively large, by adopting the arrangement provided by this embodiment of the present disclosure, the voltage drop of the first power supply voltage PVDD can be compensated by the voltage drop compensation unit, thereby compensating the influence of the change of the first power supply voltage PVDD on the drive current of the sub-pixel, improving the brightness stability of the first display region Aand the second display region A, further improving the brightness uniformity of the display panel, and weakening the flickering problem.

In an embodiment of the present disclosure, the voltage drop compensation unitmay compensate the voltage drop of the first power supply voltage PVDD in real time, or may delay a period of time, for example, delay one frame for compensation.

In an embodiment, with reference toand,is a modular schematic diagram of a voltage drop compensation unit according to an embodiment of the present disclosure, and the voltage drop compensation unitincludes a voltage detection sub-unitand a compensation calculation sub-unit. The voltage detection sub-unitis configured to detect an actual value of a first power supply voltage PVDD received by the pixel drive circuit. The compensation calculation sub-unitis configured to calculate a difference between the actual value and an ideal value of the first power supply voltage, and send a compensation value generated according to the difference between the actual value and the ideal value, to the data drive circuit. The data drive circuitmay provide the compensated data voltage DATA to the pixel drive circuitaccording to the compensation value.

In an embodiment of the present disclosure, as shown in, which is a modular schematic diagram of a display apparatus according to an embodiment of the present disclosure, the display apparatus includes a drive IC. The drive ICincludes a timing controller. The timing controlleris electrically connected to the drive controller. The drive controlleris configured to output a mode control signal to the timing controller. The mode control signal is configured to enable the timing controllerto control the display panelto switch between the multi-frequency mode and the conventional mode. As shown in, the timing controlleris electrically connected to the gate drive circuitand the data drive circuit.

In an embodiment, at least one of the drive controller, the gate drive circuit, and the data drive circuitmay be integrated into the drive IC.illustrates that the drive controller, the gate drive circuitand the data drive circuitare all integrated into the drive IC.

In an embodiment of the present disclosure, as shown in, which is a schematic block diagram of a display apparatus according to another embodiment of the present disclosure, the display apparatus further includes an application management module, and the application management moduleis electrically connected to the timing controller. In this embodiment of the present disclosure, the drive controllercan also be integrated into the application management module.